Simple design of a six-band terahertz perfect metasurface absorber based on a single resonator structure

In this paper, we present a simple design of six-band terahertz (THz) perfect metasurface absorber (PMSA) composed of a single circular-split-ring (CSR) structure placed over a ground-plane by a dielectric substrate. The average absorbance of 99.1% at six distinct frequencies can be obtained for the proposed PMSA under normal incident THz wave. The distribution characteristics of electric field reveal that the six absorption peaks of the proposed PMSA mainly originate from the combination of the higher-order localized surface plasmon (LSP) and propagating surface plasmon (PSP) resonance modes. Moreover, the influences of geometric parameters on the resonance absorption properties of PMSA were investigated numerically. Owing to its excellent properties, this design of the six-band PMSA may have potential applications in imaging, sensing and detection.